Method for solvent-free skin care products

ABSTRACT

We report a method of manufacturing solvent-free skin care products by substituting volatile organic compounds for polysorbate surfactants. A minimum effective concentration of food-grade polysorbate surfactants resulted in a fragrance composition that naturally separates layers following homogenization with gentle mixing.

RELATED TO application Ser. No. 16/270,606

BACKGROUND Field of the Invention

This invention concerns novel liquid skin care compounds and theirmethod of production.

Background of Invention

Traditional Organic Solvents (TOS) are chemicals such as alcohol,acetone, ethers, and chloroform that are used in fragrances to mix oiland aqueous phases to a single layer.

TOS are generally toxic substances that may be irritating to sensitivemucosal tissues including the skin, eyes, olfaction, and inner lining ofthe respiratory system.

Further, TOS have been associated with denaturing the active state ofvitamins and nutrients that may be added to fragrances for skin health.

TOS are generally carcinogenic and harsh chemicals. Thus, it isdesirable to have a method of manufacturing skin care products that donot contain TOS.

SUMMARY OF INVENTION

The method of this invention is centered around the use of polysorbatesurfactants as a replacement for organic solvents or alcohol in skincare compounds. The invention results in a liquid product with separateoil and water phases that homogenize following gentle shaking.

The invention is the minimum effective polysorbate surfactantconcentration to homogenize oil and water layers. Polysorbatesurfactants are a type of nonionic surfactants, and surfactants aresoap-like substances whose chemical structure is similar to fats. Theydo not evaporate at room temperature as do solvents.

The minimum concentration of commercially available food-gradepolysorbate surfactants were measured to be similar. The minimumconcentration ranged as low as 2% total-oil-wt and always less than 5%total-oil-wt.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1: shows the natural separation of oil and aqueous layers in afragrance solution without solvents and without surfactants in a settledstate. The oil layer is demarcated with dashed lines.

FIG. 2: shows the natural mixture of oil in water in a fragrancesolution without solvents and without surfactants after mechanicalstirring.

FIG. 3: shows the natural separation of oil and aqueous layers in afragrance solution with the minimal effective concentration ofpolysorbate surfactants in a settled state. The oil layer is demarcatedwith dashed lines.

FIG. 4: shows the homogeneous mixture of oil and aqueous layers in afragrance solution with the minimal effective concentration ofpolysorbate surfactants after mechanical stirring.

TABLE 1: shows the minimum effective concentration of variouspolysorbate surfactants in a 20% oil formulation at 50 mL total volumeto completely homogenize oil and water layers, while concentrationsbelow these were not found to fully homogenize water and oil layers.

DETAILED DESCRIPTION OF INVENTION

Oil and water do not mix unless there is an agent to facilitate theirmixture. Organic solvents are widely utilized in the manufacturing ofskin care products to blend oil and aqueous layers in to one homogeneousliquid layer. However, these solvents have also been found to havedetrimental effects against the bioactive state of nutrients.

It is desirable for oil and water to homogenize in order to evenlydisperse fragrant components in a liquid skin care product, and to below enough in viscosity to conveniently dispense with standard atomizersand sprays. Also, the applicant of this product should not feel oily aswould be the case with natural oil products.

An “organic solvent” is a type of volatile organic compound (VOC). VOCsare organic chemicals that can evaporate at room temperature.Classifications of organic solvents include chlorinated solvents,allopathic hydrocarbons, alcohols, glycols, esters, ethers, andaldehydes. Specific examples of organic solvents include alcohol,chloroform, and acetone. Almost every organic solvent is health hazard.

In addition to their general toxic characteristic, VOCs have been foundto denature vitamins, coenzymes, and enzyme proteins.

The present invention provides a skin care composition that eliminatesthe use of VOCs by substituting them with polysorbate surfactants tohomogenize oil and aqueous layers.

Polysorbate surfactants are a type of anionic surfactant. They behavelike soap, and mix water and oil. High concentrations of polysorbatesurfactants may result in soap bubbles or suds. Here, we were interestedto utilize the minimum concentration of polysorbate surfactants to mixoil and water layers of nutriated skin care compounds.

The stability and relative nontoxicity of polysorbate surfactants allowsthem to be used as detergents and emulsifiers in a number of domestic,scientific, and pharmacological applications. They are also found infood products, hence, they may be referred as “food-grade”.

A minimum concentration of polysorbate surfactant was defined byvolumetric titration into various fragrance composition mixtures rangingfrom 10-50% oil in water on a stirring plate with continuous stirring.The results were similar across polysorbate types and found to be as lowas 2% total-oil-wt of compounds, and always below 5% total-oil-wtconcentration.

The amount of time required for the oil and water layers to separate forvarious concentrations of polysorbate surfactants was measured. Thesewere determined to be as low as 30 seconds for the lowest concentrationsand as high as one minute or more for higher concentrations. All of theconcentration ranges were found to result in a separation of oil andwater layers once the compound is allowed to settle.

The object of the present invention is a minimum polysorbate surfactantconcentration to substitute the use of VOCs. Our concentration was foundto be effective to homogenize oil and aqueous layers following gentleshaking. For our purposes, the natural separation of oil and aqueouslayers is desired as a visual indicator that VOCs are not used.

The homogenized solutions also displayed favorable viscositycharacteristics for the dispersion of the liquid fragrance product withstandard atomizers and sprays. With this system, the fragrance in it'ssettled state will have a separation of the oil layer from the aqueouslayers, thus requiring the user to mix layers with gentle shaking priorto the application of the fragrance to their body or skin. Further,since there are no VOCs this product may be used on animals and inclinical settings.

The absence of VOCs and organic solvents provides a suitable environmentfor the addition of nutrients to the fragrance composition, includingwater soluble vitamins, oil soluble vitamins, and coenzymes. The absenceof VOCs eliminates any damage to the bioactive properties of nutrientscaused by solvents.

The present invention can therefore result in a liquid skin care productthat can be applied through conventional atomizers and sprayers, thatpromotes nutrient availability in their active state, and avoidsirritation to the skin, olfaction, and respiratory systems due to theabsence of VOCs in the composition.

1. A method for preparing liquid skin care products without organicsolvents.
 2. A method for preparing liquid skin care products withfood-grade polysorbate surfactants including PEG-20, PEG-60, and PEG-80.3. A method for preparing liquid skin care products with any liquidpolysorbate surfactant types.
 4. A method according to claims 2 and 3 attheir minimal concentrations.
 5. A method according to claim 4 at aconcentration as low as 2% total-oil-wt and always below 5% total-oil-wtof the final composition.
 6. A method according to claim 5 wherein anylower concentration would not homogenize water and oil layers followinggentle shaking.
 7. A method according to claims 1-6 of manufacturingsolvent-free liquid skin care products.
 8. A method according to claim 7wherein solvents are not used and do not exist.
 9. A method according toclaim 8 that eliminates the denaturing of bioactive nutrients caused bysolvents.
 10. A method according to claims 8 that eliminates thedenaturing of essential oil benefits and mineral nanostructures causedby solvents.
 11. A method according to claims 7 and 8 wherein thecomposition is a liquid product.
 12. A liquid skin care productaccording to claims 7-11 wherein added nutrients have no loss ofbioactive potency caused by the presence of organic solvents.
 13. Aliquid skin care product according to claims 7-11 wherein addednutrients have no loss of essential oil and mineral benefits caused bythe presence of organic solvents.
 14. A liquid skin care productaccording to claim 11 that dispenses with standard atomizers and sprays.15. A liquid skin care product according to claim 11 that always forms abilayer (i.e. separation of oil and water layers) after allowing thesolution time to settle.
 16. A liquid skin care product according toclaim 11 that fully homogenizes following gentle shaking.
 17. A liquidskin care product according to claim 11 that would not homogenize withlower concentrations according to claim
 6. 18. A liquid skin careproduct according to claims 1-17 that behave similarly across differentfood-grade polysorbate surfactant types including PEG-20, PEG-60, andPEG-80.
 19. A liquid skin care product according to claims 1-18 thatdoes not use any other products to homogenize oil and water layers. 20.A liquid skin care product according to claims 1-19 that naturallyseparates oil and water layers 90 seconds or less after allowing thesolution time to settle.